Module src.olaaaf.formula.naryFormula.orOperator

Class representing the Or operator as a relation with an arity equal or greater than 1 in PCMLC as a syntax tree.

Classes

class Or (*formulas: Formula, fmName: str = None)

Class representing the Or operator as a relation with an arity equal or greater than 1 in PCMLC as a syntax tree.

Parameters

*formulas : list of olaaaf.formula.formula.Formula
The formulas meant as components of the Or operator.

Attributes

children : set of olaaaf.formula.formula.Formula
The children of the current node.
Expand source code 
class Or(NaryFormula):
    '''
    Class representing the Or operator as a relation with an arity equal or
    greater than 1 in PCMLC as a syntax tree.

    Parameters
    ----------
    *formulas: list of `olaaaf.formula.formula.Formula`
        The formulas meant as components of the Or operator.

    Attributes
    ----------
    children: set of `olaaaf.formula.formula.Formula`
        The children of the current node.
    '''
    
    _symbol = "OR"
    
    def toDNF(self) -> Formula:
        '''
        Method returning the current Formula in Disjunctive Normal Form.

        Returns
        -------
        `olaaaf.formula.formula.Formula`
            The current Formula in Disjunctive Normal Form.
        '''
        
        return Or(*{child.toDNF() for child in self.children})
    
    def _toDNFNeg(self) -> Formula:
        '''
        Protected method used in the algorithm to recursivly determine the
        Disjunctive Normal Form, used when a Negation is in play instead of toDNF().

        Returns
        -------
        `olaaaf.formula.formula.Formula`
            The current Formula in Disjunctive Normal Form under Negation.
        '''
        
        from .andOperator import And
        
        dnfChildren = {child._toDNFNeg() for child in self.children}
                        
        orChildren = set()
                        
        for dnfChild in dnfChildren:
            if isinstance(dnfChild, Or):                
                orChildren.add(dnfChild)

        dnfChildren = dnfChildren - orChildren
                
        if len(orChildren) == 0:
            return And(*dnfChildren)
                                        
        combinations = [{orChild} for orChild in orChildren.pop().children]
        
        tempcomb = []
        for orChild in orChildren:
            for elem in orChild.children:
                for comb in combinations:
                    tempc = comb.copy()
                    tempc.add(elem)
                    tempcomb.append(tempc)
            combinations = tempcomb
            tempcomb = []

        dnfFormula = {And(*comb.union(dnfChildren)) for comb in combinations}
            
        return Or(*dnfFormula)
    
    def getAdherence(self, var : Variable = None) -> list[list[Constraint]]:
        '''
        Returns a 2D list containing all the constraints of the adherence of 
        the Formula, in Disjunctive Normal Form.

        Attributes
        ----------
        var : olaaaf.variable.variable.Variable
            Variable used in case of inequality.

        Returns
        -------
        list of list of olaaaf.formula.nullaryFormula.constraint.constraint.Constraint
            2D list containing all the constraints of discute vraiment de l'implémentationthe adherence of the Formula,
            in Disjunctive Normal Form.
        '''
        
        res = []
        
        for children in self.children:
            for reschildren in children.getAdherence(var):
                res.append(reschildren)
                
        return res
    
    def _getAdherenceNeg(self, var : Variable = None)  -> list[list[Constraint]]:
        '''
        Protected method used in the algorithm to recursivly determine the
        constraints of the adherence of the Formula, used when a Negation is in play
        instead of getAdherence().

        Attributes
        ----------
        var : variable used in case of inequality

        Returns
        -------
        list of list of Constraint
            2D list containing all the constraints of the adherence of the Formula,
            in Disjunctive Normal Form under Negation.
        '''
        
        res = []
        
        for children in self.children:
            for reschildren in children._getAdherenceNeg(var):
                for const in reschildren:  
                    res.append(const)
                    
        return [res]
    
    def toLessOrEqConstraint(self):
        '''
        Method used to transform a `olaaaf.formula.formula.Formula` into another one, with only `olaaaf.formula.nullaryFormula.constraint.constraintOperator.ConstraintOperator.LEQ` constraints.

        Returns
        ------
        `olaaaf.formula.formula.Formula`
            A `olaaaf.formula.formula.Formula` with only `olaaaf.formula.nullaryFormula.constraint.constraintOperator.ConstraintOperator.LEQ` constraints.
        '''
        childrenModified = set()
        
        for child in self.children:
            childrenModified.add(child.toLessOrEqConstraint())

        return Or(*childrenModified)
        
    def toPCMLC(self, varDict) -> Formula:
        '''
        Method used to transform a `olaaaf.formula.formula.Formula` into a new one, in the PCMLC formalism.

        Parameters
        ----------
        varDict : dictionnary
            Dictionnary used to tell which variable should be replaced by which.

        Returns
        -------
        `olaaaf.formula.formula.Formula`
            A `olaaaf.formula.formula.Formula` in the PCMLC formalism.
        '''
        return Or(*{formul.toPCMLC(varDict) for formul in self.children})

    def _toPCMLCNeg(self, varDict) -> Formula:

        from . import And

        return And(*{formul._toPCMLCNeg(varDict) for formul in self.children})

    def _getBranches(self):
        '''
        Method used to get the branches of the analytic tableau representing the `olaaaf.formula.formula.Formula`,
        automatically removing any closed one once it's caught. 

        Returns
        ------
        `list[dict[Constraint, bool]]`
            A list of all branches, represented by a dictionnary matching every atom
            `olaaaf.formula.nullaryFormula.constraint.constraint.Constraint` to a `bool` representing if it has a negation (`False`)
            or not (`True`).
            If all branches are closed, return `None`.
        '''
        
        branchesList = list()

        for child in self.children:
            branch = child._getBranches()

            if branch is not None:
                branchesList += branch

        # Si aucune branche n'est satisfiable, on retourne None
        if len(branchesList) == 0:
            return None

        return branchesList 

    def _getBranchesNeg(self):
        '''
        Method used to get the branches of the analytic tableau representing the `olaaaf.formula.formula.Formula`,
        automatically removing any closed one once it's caught. 
        Used when a Negation is in play instead of `_getBranches()`.

        Returns
        ------
        `list[dict[Constraint, bool]]`
            A list of all branches, represented by a dictionnary matching every atom
            `olaaaf.formula.nullaryFormula.constraint.constraint.Constraint` to a `bool` representing if it has a negation (`False`)
            or not (`True`).
            If all branches are closed, return `None`.
        '''

        branchesList = [child._getBranchesNeg() for child in self.children]
        fullBranches = list()

        for product in itertools.product(*branchesList):

            mergedProduct = dict()

            for literal in product:

                for atom, isNotNeg in literal.items():

                    if atom not in mergedProduct:
                        mergedProduct[atom] = isNotNeg
                    elif mergedProduct[atom] != isNotNeg:
                        mergedProduct = None
                        break
                
                if mergedProduct is None:
                    break
            
            if mergedProduct is not None:
                fullBranches.append(mergedProduct)

        if len(fullBranches) == 0:
            return None
        
        return fullBranches

    def __str__(self):

        symbol = Constants.OR_STRING_OPERATOR

        if len(self.children) == 1:
            return str(list(self.children)[0])
        
        s = ""
        for child in self.children:
            s += "(" + str(child) + ") " + symbol + " "
        toRemove = len(symbol) + 2
        s = s[:-toRemove] + ""
        return s
    
    def toLatex(self):
        r"""
        Method returning a \(\LaTeX\) expression representing the Formula. Operators are customisable in `olaaaf.constants.Constants`.
        
        Returns
        -------
        String
            The \(\LaTeX\) expression representing the Formula.
        """

        symbol = Constants.OR_LATEX_OPERATOR

        if len(self.children) == 1:
            return list(self.children)[0].toLatex()
        
        s = ""
        for child in self.children:
            s += "(" + child.toLatex() + ") " + symbol + " "
        toRemove = len(symbol) + 2
        s = s[:-toRemove] + ""
        return s

Ancestors

Methods

def getAdherence(self, var: Variable = None) ‑> list[list[Constraint]]

Returns a 2D list containing all the constraints of the adherence of the Formula, in Disjunctive Normal Form.

Attributes

var : olaaaf.variable.variable.Variable
Variable used in case of inequality.

Returns

list of list of olaaaf.formula.nullaryFormula.constraint.constraint.Constraint
2D list containing all the constraints of discute vraiment de l'implémentationthe adherence of the Formula, in Disjunctive Normal Form.
def toDNF(self) ‑> Formula

Method returning the current Formula in Disjunctive Normal Form.

Returns

olaaaf.formula.formula.Formula The current Formula in Disjunctive Normal Form.

Inherited members